Head for barrels



July 23, 1940. G. MULLER Y 208,773

HEAD FOR BARRELS Filed Jan. '29, 1937 INVENT OR.'

' ATTORNEY.

Patented July 23, 1940 UNITED STATES PATENTol-"FICE HEAD FOR. BARRELS Georg Mller, Leipzig, Germany Application January 29, 1937, Serial No. 122,904 In Germany January 29, 1936 7 Claims.

l fervescing contents, as beer and mineral water.

It has been a custom for centuries to make the heads or bottoms of such barrels or casks out of massive and solid heartwood and quartergrain oak. Where these heads had to be bevelled or mitered along their outer edge, the capillariesA of the wood were cut and thus mutilated and exposed, and that was unsatisfactory from the point of view of hygiene. For the heads of barrels that only have to withstand limited pressure it has been suggested to use a plurality of plies of wood. But when such heads are called upon to resist a higher pressure, and must therefore be executed in greater thicknesses of wood, the edges have to be chamfered again and the capillaries of the wood are cut and become exposed as before.

According to this invention a head of a barrel or cask, i. e. its top or bottom is arched or depressed at the center towards the interior of the barrel or Cask before it is placed thereinto. In order to make it possible to cut the grooves strictly radially into the staves and also to be able to make the sides of the grooves parallel to each other, the head, when formed, is pressed with a flat, level outer margin.. For the surface plies of the head quartergrain or heartwood should be used, if the head is built up in layers-so that the strata of grain, especially on the side of the head facing the interior of the barrel or cask, pass uninterruptedly through and the capillaries of the wood are not cut. Various layers of a head may be rmly bound upon each other by an adhesive. i

The forming of the head is done in such a way that the angle upon the inside, between the side wall and the head of the barrel or cask is rendered as obtuse as possible, so that dirt cannot accumulate and bacteria are not offered a breeding place.

By these arrangements the folowing advanv= tages are obtained:

The head assembled from layers of wood under pressure, possesses a continuous and smooth surface on the side facing the interior of ythe barrel or cask; and the capillaries are not cut nor laid open at said surface. All danger that blisters are formed when pitch is applied, the scaling off of pitch, slivering and the growth of bacteria are thereby eliminated. 'Ihe liquid cannot penetrate the wood of the casing.

A head of this invention adapted uniformly to withstand and to react upon the pressures applied thereto, weighs less than a massive and integral one. In a massive head the edge must be bevelled, as the groove for receiving the head cannot exceed a predetermined width. Because the bottom of the groove in the staves represents a weakened portion of the wall which cannot withstand a high fluid pressure when it has more than said predetermined Width. Nor can,- in such a case,-said weakened portion of the wall be closed around the periphery of `the head so tight that the pressure uid cannot leak in though the hoops may 4be properly mounted.v

Furthermore the shrinkage occurring when the head dries in must be reduced to a minimum.r

The head, or at least the curved part thereof, resembles a segment of a hollow sphere, beinggenerally speaking-deformed into saucer shape; Such a segment radially expands when flattened by compression. pressed tighter into the groove, and tightens all the better, the more it yields to fluid pressure exerted from the interior of the barrel or cask. When flattened under the bending stress the innermost layer of the head at its exposed surface in particular, gains more in diameter than the others, so that the liquid meets with an especially strong resistance at the edge of the innermost circumference 4of the head and I provide the tightest seal at that circle. By way of contrast a slight bending through an outward bulging of a massive head of the old art always causesl a diminution of contact and abutment of th-e nner edge of a head with the groove of the stave.

The flat, level marginal annular part of the head creates a smooth, obtuse angle between the inner surface of the casing of the staves and the .head of the barrel or cask which offers no quarters for the breeding of bacteria.

From the manufacturers point of view the flat, level margin has the additional advantage of'allowing both sides of the groove to be cut in parallelism with each other. Furthermore, when the head is compressed and expands in diam# eter the angle between the staves and head practically does not undergo any alteration.

For barrels of large diameter it is preferable to execute the head stronger at and around its central portion than near the edge, e. g. by inserting layers of smaller diameter which are pressed in.

Several modifications of vthe invention are schematically shown in the annexed illustration.

Fig. l shows theends of a cross-sectioned barrel and heads of my invention into the barrel.

Fig. 2 illustrates in a similar View, a head which is reinforced at the center by the insertion of the concentric discs of smaller diameter. In this and in the next figure the end of the barrel indicated inA a dot-dash line.

Fig. 3 shows in a similar view a depressed head with a flat margin strengthened by the insertion of concentric discs of smaller diameter.

Fig. 4 shows a depressed head with a flat marisl 1.5. Therefore, the head is also ally expanded into the groove c.

gin, like that of Fig. 1 or Fig. 3, in a perspective representation.

The heads, which have been manufactured in conformity with this invention, are placed into the grooves or Crozes c in the staves b of the barrel. The heads may consist of superimposed layers of wood squeezed together under a high compression. The layers or plies may be additionally interconnected by a suitable adhesive. The layers, especially the inside surface layer d, and also the outer layer e, are made out of resistive wood, e. g. heartwood or quartergrain. The heads or the layers to be formed are shaped and compressed in highly polished forms; and We obtain a smooth, uniformly continuous, al,- solutely tight surface on an integral layer of wood. The center of the head is shaped concave. In order to be able to out the grooves with parallel, level sides, and for other reasons, the margin of the head may remain or be pressed level and flat. Reacting upon the pressure of the contents of the barrel, the inner surface of the head may flatten to a limited degree and the diameter of the head may increase slightly, so that head is firmly pressed into the groove c. Owing to the arched inner surface the head reacts over its entire surface with practically the same resistance, and when yielding is radi- Since the margin of the head is shaped to extend in a level plane, it forms with the outwardly flaring wall of staves an obtuse angle. At the obtuse angle the barrel is easy to clean and the faces are perfectly smooth. In such an arrangement dirt cannot accumulate and bacteria will not breed.

For barrels of a very large diameter the heads or bottoms are strengthened in the middle as shown in Figs. 3 and 4. For this purpose one or more concentric radially, evenly attenuated discs z' and kof smaller diameter than the outer lay ers are arranged between the latter.

The barrel of Fig. 1 shows the plywood staves b to be held together by hoops h and their ends are reinforced by inserted plies, so lthat the crozes c do not weaken the barrel ends excessively. Opposite sides of the crozes c extend flat and parallel with each other. The plies of the heads are substantially even in thickness so that the surface plies are substantially par? allel with each other and the head has a flat margin fitting the croze. The major, central portion a of the head is pressed into saucer shape, the barrel having therefore outward concavities a at the ends. But in the embodiment of Fig. 2 such concavity is avoided and the outer surface of the barrel head is flat throughout, because the disc i fills the ooncavity of the inside cover element d. In spite of filler discs i and 1c an outer concavity a shows on the head of Fig. 3, because here the central saucer shape is more pronounced.

I -Iaving thus described lin detail several outstanding aspects of my invention, it will be realized that other modifications and changes may be resorted to under special conditions.

I therefore do not wish to be limited and restricted to the exact details shown and described, but reserve the right to make such changes and modifications as may fairly fall Within the scope of the subject matter now being claimed.

What I claim is:

1. In a head for barrels to accommodate fluids under pressure, outside layers of heartwood or quartergrain, and layers of a smaller diameter for the formation of a strengthened middle of the head, all said layers being under high pressure and by aid of a binding'agent joined tog-ether and formed with a fiat margin and a concave center.

2. A laminated head comprising a one-piece Wooden cover member which is cut throughout with the grain of the wood producing a iiat margin with substantially no cross-cutting nor mutilation of the grain in the marginal portion, said member being substantially uniform in thickness, the major, central portion of the member being deformed into saucer shape.

3. A laminated head comprising one-piece wooden cover members upon opposite sides of said head, said members being cut throughout with the grain of the wood at a substantially uniform thickness and having both flat marginal portions with substantially no cross-cutting nor mutilation of the grain of the outer surfaces of such portions, the major, central portion of one of said members being deformed into saucer shape.

4. A laminated head vcomprising one-piece wooden cover members upon opposite sides of said head, said members being cut throughout with the grain of the wood at a substantially uniform thickness and having both fiat marginal portions with substantially no cross-cutting nor mutilation of the grain of the outer surfaces of such portions, the major, central portions of said members being deformed into saucer shape.

5. A laminated head comprising one-piece wooden cover members upon opposite sides of said head, said members being cut throughout with the grain of the wood at a substantially uniform thickness and having both flat marginal portions with substantially no cross-cutting nor mutilation of the grain of the outer surfaces of such portions, the major, central portion of one f" of said members being deformed into saucer shape, and a filler in the concave side of said major, central portion of said one member.

6. A laminated head comprising substantially parallel one-piece wooden cover members upon opposite sides of said head, said members being cut throughout with the grain of the wood at a substantially uniform thickness and having both fiat marginal portions with substantially no cross-cutting nor mutilation of the grain of the outer surfaces of such portions, the major, central portion of one of said members being deformed into saucer shape.

7. A barrel having at one end a laminated head comprising upon the inside a one-piece wooden cover member which is cut vthroughout with the grain of the wood producing a flat margin with substantially no cross-cutting nor mutilation of the grain in the marginal portion, said member being substantially uniform in thickness, the major, central portion ofthe member being deformed into saucer shape, and having side out with a croze shaped to receive said head, said Croze having a flat side upon which abuts said cover member of the head.

GEORG MLLER. 

